Ulf Jasper’s u-color-cycle.el smoothly
changes the color of all text in a window or region while you stare at
it, mesmerized. It reminds me of those setcolor tricks I used to do in
grade school and high school. u-color-cycle.el is a cute, harmless
diversion that just goes to show Emacs hackers have way too much time
on their hands. ;) (This is a Good Thing.)